3‑(Dicyanomethylidene)indan-1-one-Functionalized Calix[4]arene–Calix[4]pyrrole Hybrid: An Ion-Pair Sensor for Cesium Salts

A chromogenic calix[4]­arene–calix[4]­pyrrole
hybrid ion pair
receptor bearing an indane substituent at a β-pyrrolic position
has been prepared. On the basis of solution-phase UV–vis spectroscopic
analysis and 1H NMR spectroscopic studies carried out in
10% methanol in chloroform, receptor 1 is able to bind
only cesium ion pairs (e.g., CsF, CsCl, and CsNO3) but
not the constituent cesium cation (as its perchlorate salt) or the
F–, Cl–, or NO3– anions (as the tetrabutylammonium salts). It thus
displays rudimentary AND logic gate behavior. Receptor 1 shows a colorimetric response to cesium ion pairs under conditions
of solid–liquid (nitrobenzene) and liquid–liquid (D2O–nitrobenzene-d5) extraction.